BIRDS IN RICE PADDY ECO-SYSTEM
Translated and adapted from Malayalam to English for PADDY by Usha S
Paddy is one of the most important grains in the developing world. It is cultivated in at least 114 countries, in an area of 156 million hectares. Half of the world population is dependent on paddy rice for their food. Hence there is an economic system developed based on paddy rice and there is a unique art and culture based on rice .
Rice is thus connected to our lives intricately. Rice culture has led to the formation of a unique ecosystem, which is dynamic due to the changes in the cultivation methods and the micro climate. Paddy lands, bunds along the field, the cultivable land lying close to the paddy fields, hedges, small streams, microbial population, fauna and flora together forms this ecosystem. It can be called the paddy ecosystem. Birds, reptiles, mammals etc are all visitors in this ecosystem. The relationship among all these components contributes to the sustainability of the paddy ecosystem.
Birds and paddy culture Among the different kinds of animals that depend on the paddy ecosystem, birds are the most important group. Most of the paddy fields around the world are wetlands. This attracts a lot of water birds into the paddies. Apart from this paddy fields attract many birds which stay in the nearby garden lands, grass lands, scrub jungles etc. Birds depend on paddy fields not only for their food but also for breeding at various stages. In order to protect itself from other animals birds depend on the paddy fields. Paddy fields are a good place for the birds to stay covered and undetected.
Not only the paddy lands, but the nearby upland farms and the wild areas are all visited by birds. There are birds which depend on such up-land areas for breeding, but depend on paddy fields for food. There is this interconnectedness between paddy land and the surrounding landscape. Similarly birds are connected to other life forms in the paddy fields like fishes, reptiles, insects, butterflies, microbial flora and fauna etc. World over birds are considered as indicators of environmental change.
Birds control hundreds of cycles such as water cycle, food cycle and nutrition cycle. They indicate the health and the quality of our environment and respond quickly to environmental changes .They also have an important role in our food web. Minor changes among flora and fauna in the lower reaches is reflected in the habits and breeding patterns of birds. Therefore, studying birds consistently and over a period of time is important, particularly, in a fast changing ecosystem such as paddy.
When we start observing birds in the paddy ecosystem it can be seen that different kinds of birds come to paddy fields during different stages of growth. It is interesting to watch birds move their position along with the plough from one end of the field to other side along the furrows.
During planting time when there is standing water in the fields certain types of birds come, whereas during harvest another set of birds visit the fields. During fallow periods yet another set of birds visit. Thus it varies between different cropping stages and seasons, the number of birds also varies. Traditional farmers had an understanding about when birds come, what they do etc. They treated birds as friends and part of their farming system.
Birds and pesticides
Modern farming methods using a lot of chemicals have impacted birds significantly. Most of the chemicals used in agriculture are toxic and hence poisonous. When farmers use pesticides, it will not stop acting with the target pests alone .These chemicals impact all exposed living organisms including soil organisms. When soil organisms die, other creatures that depend on them also die and their number reduce gradually .
This indirectly impacts the birds. If pesticides are applied in the field during the breeding cycle of birds they do not get enough food to feed the chicks. Their prey gets killed by pesticides. Usually breeding only happens when there is enough food/prey around. With loss of food, breeding is declining among birds. They are also directly impacted, for instance, they get poisoned through contaminated water and soil. Birds consume granular pesticides thinking that they are grains. Seeds coated with pesticides also are eaten by birds. Sometimes the birds die suddenly, sometimes the impact is slow.
It depends on the kind of pesticide, season of application, exposure time, amount of pesticide that gets in to their system, and the general health of the birds. Some of the commonly observed problems among birds that are exposed to pesticides are: egg shell thinning, deformities in the egg, slow growth of the chicks, Lack of care of chicks during breeding time, Loss of immunity, Loss of capability to protect itself from other animals, Loss of thermal regulation in the body, reproductive disorders and hormone system disorders and inability to navigate and find directions during migration.
In India large amount of pesticides of different kinds are used in paddy fields. From a study in South India it was found out that 45 different kinds of pesticides are used in paddy cultivation. This would definitely be impacting the birds, but there aren’t enough studies to show the relationship between decline of certain birds and pesticides. The studies that have been conducted on birds in the paddy fields is limited to twice-yearly census .This census taking does not bring out all the inter-linkages between birds and paddy eco-system.
The changes to birds and biodiversity in the rapidly changing paddy eco-systems have not been studied sufficiently by researchers or farmers. There are a few good studies done and below mentioned are a few important studies. - In 1991 Wildlife and National Parks Department of Malaysia did a study in the paddy fields and found out 158 species of birds that are dependent on paddy ecosystem. Some of these were migrants. - In 1998 in another study found out a lot of birds which are dependent on paddy grains like munias and sparrows - In the year 2000 Sundar and Subramanian did a study on the birds in the paddy ecosystem in India and found 351 varieties of birds in the paddy eco-system.
Out of this 34 varieties were breeding in the paddy fields. - In 2010, in Europe, Lee Geiger did a study comparing chemical and organic paddy fields in six European countries where paddy is grown. He found out that organic paddy fields have more diversity of birds than chemical paddy fields. In addition to pesticides, weedicides also contribute to loss of food /prey of birds. Many insects depend on weeds for their breeding. Birds also feed directly on seeds of weeds. So when weeds are removed by using weedicides birds lose their food.
For example, studies in England have shown that due to the use of weedicides the grey partridge faces extinction. Another example from England is of linnets becoming rare due to the continued use of weedicides. Their main food was the seeds of some weed plants. When weedicides are applied birds also lose their breeding spaces. Some birds breed on the hedge plants in the field and nearby wild weedy places which get removed by weedicides.
Ecological importance of birds
1. Insectivorous birds like warblers are extremely important as they help us to control pests. One single warbler eats a minimum of 1500 insects in a single day.
2. Birds like flower peckers and sunbirds act as pollinators.
3. Seed dispersion is an important activity undertaken by birds.
4. Scavengers like crows and vultures help us cleaning up the environment
5. Raptors and owls are excellent predators. They are helpful to farmers in controlling rats and problematic insects.
6. Excreta of birds is good manure
Experience from Padetti, Palakkad, Kerala
The Kerala State Biodiversity Board had a project in Padetti village in Palakkad District, from 2008 to 2011, called the Agrobiodiversity Restoration Programme, to look at the impact of organic farming on biodiversity. The project area included 100 acres of paddy fields and 300 acres of garden land and some forest patch and 69 farming families were part of this project. While the project was implemented with the help of Thanal, a policy and research group, the Board also did a biodiversity monitoring through various agencies.
Along with this a continuous monitoring of birds was undertaken both in the organic field and a nearby conventional field. The study brought out a good picture of bird diversity and the importance of paddy cultivation to birds and vice versa. 145 species of birds, belonging to 50 families, were indentified. Out of this 21 were migratory birds and 46 were water birds. Some endangered species were also identified .Out of the 39 species that breed in this ecosystem, 21 species were found to depend on paddy fields during their breeding period. In the organic paddy fields 55 species of birds were found while in the chemical paddy fields only 39 species were seen. The count of birds in the two fields were also different.
On an average daily 230 birds were counted in the organic fields, while in the chemical field it was only 143. One of the important observations was that of the 145 species of birds, 52 were found feeding on insects. Obviously this means these birds help in insect control in the fields. 33 species are carnivores like owls, kites egrets etc which shows that paddy lands contain a lot of biodiversity that can take care of all these birds.
Six species observed are dependent on fishes. Nineteen specialist bird species were also observed which needs special attention because these could be especially impacted by the modern farming methods and landscape changes. In this context, one observation by the Salim Ali centre for Ornithology and Natural History (SACON) is interesting. When the project began in Padayetti nests of baya weavers were absent in the area (this used to be a very common sight in Palakkad in the coconut trees along the paddy bunds).
By the third year of the project the researchers and farmers noticed the appearance of baya weaver nests in the coconut trees along the bunds. Farmers were very happy to see them again in their village, and motivated many farmers to change their practices. When the surveys of 2009 and 2011 were compared, we could find some changes in the abundance of certain bird species. The abundance rate of Indian peafowl and whitebrowed bulbul has increased. There was also slight increase in the abundance rate of certain other species such as red-vented bulbul, common tailorbird, jungle crow etc.
To get a more reasonable picture of the species diversity of the area regular, continuous monitoring has to be done for a longer period. As factors like subjectivity, number of field hours, survey time, changes in agricultural pattern, soil and climate and changes in forest management can influence the bird activity of the area, there is need for multi-variate analysis. Conclusion We cannot find a single piece of land or sky in this earth without birds. From the Arctic to Antarctica, from the tropical evergreens to deserts, from rivers to sea, from rural to urban areas we can see birds.
There are around 10,000 Paddy field- Kanyakumari species of birds seen on earth. Out of these more than 5000 species are recorded from the agricultural areas, i.e. more than 50%! Therefore, along with conserving forest and other protected areas the wetlands and agricultural areas should also get priority for conservation as most of them are under the risk of destruction due to extensive human interference.
Paddy lands cannot replace wetlands, however, when wetlands are destroyed or filled up many birds start depending on paddy fields for their survival. We need paddy fields for our food security, but these birds are also dependent on them for their survival. The question we should examine is how to co-exist and develop? In this context organic / ecological paddy cultivation gains more importance. Also it is not a one way relationship; the birds are integral to the health of the eco-system. When birds survive, it will support the paddies and us. It will also contribute to sustaining biodiversity.
Paddy is not just food, it is life.